Name:	fe_ConsolidationLessThanWhollyOwnedSubsidiaryParentOwnershipInterestChangesAdditionalSaleOfInterestByParentPercent
Namespace Prefix:	fe_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

Consolidation, Less Than Wholly Owned Subsidiary, Parent Ownership Interest, Changes, Closing Sale Of Interest By Parent, Percent

No definition available.

Name:	fe_ConsolidationLessThanWhollyOwnedSubsidiaryParentOwnershipInterestChangesClosingSaleOfInterestByParentPercent
Namespace Prefix:	fe_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Changes, Sale of Interest by Parent, Percent

No definition available.

Name:	fe_ConsolidationLessThanWhollyOwnedSubsidiaryParentOwnershipInterestChangesSaleOfInterestByParentPercent
Namespace Prefix:	fe_
Data Type:	dtr-types1:percentItemType
Balance Type:	na
Period Type:	instant

Deferred Tax assets, Federal And State Income Tax Associated With The Tax Gain

No definition available.

Name:	fe_DeferredTaxAssetsFederalAndStateIncomeTaxAssociatedWithTheTaxGain
Namespace Prefix:	fe_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Deferred Tax Assets Operating Loss Carryforwards Not Subject To Expiration, Net Of Tax

No definition available.

Name:	fe_DeferredTaxAssetsOperatingLossCarryforwardsNotSubjectToExpirationNetOfTax
Namespace Prefix:	fe_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 808
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479402/808-10-50-1

Name:	us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards that are subject to expiration dates.

No definition available.

Name:	us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsSubjectToExpiration
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount, after deferred tax asset, of deferred tax liability attributable to taxable differences without jurisdictional netting.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-2

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 45
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482525/740-10-45-6

Name:	us-gaap_DeferredTaxLiabilities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The amount of cash paid during the current period to foreign, federal, state, and local authorities as taxes on income.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482913/230-10-50-2

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 25
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-25